The invention is based on a method for producing a commutator ring for a commutator. It is known to produce commutator rings from a previously engraved band material for so-called roll commutators. In this process, an optionally profiled endless band, whose width is equivalent to the later axial length of the commutator, is provided transversely to the direction of motion of the band with grooves by means of a forming tool, so that laminas that are now joined together only via webs. Depending on the number of laminas in a commutator ring, a corresponding number of laminas is cut apart from the onward-moving, now shaped band and closed to form the commutator ring. To stabilize the commutator ring and to insulate the individual laminas from one another, the commutator ring is usually embedded together with a metal hub in an insulating compound.
In order to prevent axial and radial shifting of the laminas in the later intended use of the commutator ring, it is knownxe2x80x94for instance from German Published, Examined Patent Application DE-AS 12 18 053xe2x80x94to cut barbs on the back side of the laminas for the sake of anchoring them in the insulating compound. This has the disadvantage that cutting the barbs reduces the usable thickness of the laminas of the commutator ring.
From U.S. Pat. No. 5,204,574, a commutator ring is also known which has dovetail profiles extending axially of the laminas, by means of which profiles securing of the laminas in the radial direction of the commutator is assured, but shifting in the axial direction of the commutator cannot be precluded.
To overcome this disadvantage, it is known from Published, Unexamined German Patent Application DE-OS 195 43 998, for the sake of axially securing the laminas, to design the dovetail profiles by means of a special process in such a way that via the axial spacing, an interruption of the dovetail profile is made. This production process is still relatively complex, however, making it more expensive.
In accordance with the present invention, dovetail grooves provided on the laminas are formed by simultaneous lateral furrowing of the laminas beginning at both face ends of the laminas by means of one tool each so that approximately in the middle of the laminas, a groove-free zone remains between the dovetail grooves.
The method of the invention for producing a commutator ring has the advantage over the prior art that its production is made still simpler and less expensive, and that even very special forms of the dovetail groove can be produced more simply, for the sake of especially good retention of the laminas.
Further advantages of the invention will become apparent from the ensuing description, the dependent claims, and the drawing.